Background and Identification

The Chipping Sparrow, Spizella passerina arizonae and Spizella passerina passerina, are two of five subspecies of Chipping Sparrow, four of which are found in Mexico. They are a member of the Passerellidae Family of New World Sparrows, which has one hundred thirty-two members placed in thirty genera, and one of six global species of the Spizella Genus. Their common name stems from the sharp “chip” call that they make throughout the day as they forage and interact with others. Thus, calling this species a “songbird” is a misnomer. They are known in Mexico as Chingolo Cejiblanco.

The Chipping Sparrow is a small songbird, with males and females appearing similar, although males are slightly larger. This is known as sexual dimorphism. Both sexes feature a rufous to chestnut brown crown, a distinct white superciliary line, black lores and eye stripe, a gray rump, an unstreaked gray breast, and flanks that transition into a dull white belly. During the breeding season, females develop a brood patch, and males display a cloacal protuberance. A cloacal protuberance is a structure that forms in male birds during breeding season when the cloaca, or rear orifice, enlarges due to increased sperm storage. Both sexes have olive-brown upper mandibles and salmon-colored lower mandibles. Their iris is dusky brown, and their legs and feet are also salmon-colored.

Habitat and Geographical Range

The Chipping Sparrow is widely distributed across North America. It is commonly found in open woodlands, parks, gardens, and shrubby areas, often near human habitation. It prefers to breed in shrubby, coniferous habitats bordering open grassy spaces. This species is a partial migrant, with some populations migrating south to warmer climates for the winter. Central American populations are nonmigratory.

The Chipping Sparrow is found throughout Mexico with the exception that they are absent from the Yucatán Peninsula. The arizonae subspecies is found in Baja California, northwest Sonora, southwest Chihuahua, Durango and Coahuila south to Baja California Sur and through the highlands south to Oaxaca. The passerina subspecies is found in Nuevo León and Tamaulipas. They are partial migrants with the northern subspecies moving to southern locations for wintering and the southern subspecies being year-round residents.

Common Misidentifications

The Chipping Sparrow is sometimes confused with other sparrows, particularly those with an overlapping geographical range. The American Tree Sparrow, Spizelloides arborea,  and the Clay-colored Sparrow, Spizella pallida. The American Tree Sparrow has a similar size and coloration but can be distinguished by its bicolored bill (dark upper and yellow lower) and a dark spot on its chest. The Clay-colored Sparrow is more similar in appearance but lacks the rufous crown and has a more defined facial pattern with pale lores and a distinct white stripe above the eye.

Conservation Status